aptn-ca.mx2.mx25.net has no NS records.
NS records for this zone are defined at mx25.net.
NS records for this zone are defined at mx25.net.
Question and response
Question
dig aptn-ca.mx2.mx25.net. NS
Answer
The response has no answer records.
Authority
mx25.net. 3600 SOA dns1.p01.nsone.net. hostmaster.nsone.net. 1726073215 10000 1800 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0